Posted: 11 August 2023
INOVIQ Limited (ASX:IIQ) (INOVIQ or the Company), a developer of next-generation exosome solutions and precision diagnostics, today announced results from an equivalence study to evaluate exosome-based biomarkers and performance of the EXO-OC test algorithm in 250 paired plasma and serum samples.
Background
- Proof-of-concept studies conducted by Associate Professor Carlos Salomon’s group at The University of Queensland (UQ) previously demonstrated that a potential exosome-based ovarian cancer test delivered over 90% accuracy for the detection of early-stage (stages I and II) ovarian cancer in over 450 plasma samples from asymptomatic women. The EV-based protein and miRNA biomarkers were discovered in plasma samples using Size Exclusion Chromatography (SEC) to isolate EVs.
- INOVIQ previously announced that a 97-plasma sample EXO-NET evaluation study (OC97/OCED003) was completed by UQ (ASX: 13 December 2022). The results confirmed the utility of INOVIQ’s fast, efficient and scalable EXO-NET technology for exosome biomarker discovery and development of an EV-based ovarian cancer screening test with over 90% accuracy for the detection of early-stage ovarian cancer in plasma samples.
- To date, the exosome-based Ovarian Cancer Test (EXO-OC) has been developed using plasma samples (stored for 1-5 years). To determine if long-term biobanked serum samples could be used for further development and evaluation of the test, UQ conducted an equivalence study in 250 paired serum and plasma samples (OC250/OC-ED004).
- Previous studies have reported degradation of non-exosome biomarkers during long-term storage, however, no data were available on the effect of long-term storage (up to 17 years) on exosomal biomarkers. Therefore, before proceeding to a large cohort study, it was imperative to confirm: (i) that EXO-NET performs similarly in both plasma and serum (as many of the large biobanks are serum samples); and (ii) exosome biomarkers are not affected by long-term storage.
- The objectives of OC-ED004 were to evaluate: (i) the presence of previously identified exosomebased protein and miRNA biomarkers in paired plasma and serum samples that had been stored for 14-17 years; and (ii) the performance of these biomarkers to discriminate between ovarian cancer case and control samples including in multivariate models. INOVIQ 2 | INOVIQ Limited ASX Release
Results
- Previously identified exosomal plasma protein and miRNA biomarkers were successfully identified in both serum and plasma samples.
- In samples from this long-term biobank (samples stored for 14-17 years), the exosomal biomarkers did not effectively discriminate between case and control.
- Further analysis identified differences between long- and short-term stored samples. Increased sample haemolysis, lipid concentration, EV concentration and particle size were associated with long-term storage.
- The OC-ED004 study has provided critical data that informs the ongoing development of the EXOOC test establishing that biobanked samples stored for 14-17 years were not suitable for exosome-based biomarker discovery and validation.
CSO Dr Gregory Rice said: “The OC-ED004 study provided invaluable findings for the further development of the EXO-OC test. Prior to commencing a large cohort study of biobanked serum samples it was imperative to establish the equivalence of serum and effects of long-term storage. The study identified significant differences in the behaviour of long-term storage samples when compared to recently collected samples. These differences are sufficient to necessitate the use of recently collected samples for further test development and validation. INOVIQ intends to work with UQ to identify a suitable sample cohort to progress test development.”
CEO Dr Leearne Hinch said: “The equivalence study successfully confirmed the performance of our EXO-NET pan-exosome capture tool for EV isolation in both plasma and serum samples. However, the study showed that long-term biobanked samples were not suitable for exosomal biomarker evaluation. INOVIQ now plans to source suitable plasma samples to inform further development and validation of the EXO-OC test. Underpinned by strong early data, we look forward to further advancing the EXO-OC program to fill a significant market gap, given there is currently no recommended screening test for ovarian cancer in asymptomatic women.”
EXO-OC program next development steps
The next phase of development for the EXO-OC test is to undertake a planned retrospective case-control (1:2) clinical study (OC-ED005). The study expects to be in up to 1000-samples and evaluate performance of the EXO-OC Test to discriminate ovarian cancer across all stages. Upon collection of suitable samples, the study is expected to commence in H2 FY24 and complete within 12-months
